It is well known that the speed of a target wheel can be detected using a non-contact encoder of a magnetic sensor, such as Hall sensor, anisotropy reluctance sensor and large reluctance sensor. Such sensor can be known as speed sensor, such as Two-Wire Hall Effect Directional Output Speed Sensor (TOSS), Integrated Directional Clutch Input Speed Sensor (CISS) and Non-directional Input Speed Sensor (TISS). The function, performance and design for these sensors are well known in the art. The speed sensors are capable of sensing rotational speed of a target utilized in automotive transmission application.
These speed sensors are used in both input and output encoder application during the target spinning. Typically, they have small package Integrated Chips (ICs) on the top side of magnets, with a magnet located in a carrier. During the operation process, the centering and positioning of the IC on the magnet are required to be controlled. In the prior art, the IC is generally assembled on the carrier, so that the centering between the IC and the magnet is controlled by means of the inner diameter of a hole in the carrier, and the positioning of the IC is controlled through ribs on the carrier. In this case, the magnet should has a size smaller than that of the IC in order to ensure that the centering can be performed, while the IC should be secured by an adhesive, which creates a problem of production cost.
Since the size of the magnet is smaller than that of the IC, the above solution is not suitable for a smaller IC. The operation of centering and positioning is complex, because the IC needs to be secured by an adhesive. Thus, there is a need for a positioning structure, which can be adapted to position an IC having a size smaller than a positioning magnet, and simplify the construction and operation and reduce the cost.